Two British military helicopters carrying special forces to missions inside Iraq in the hunt for al-Qaida and other high-value targets apparently crashed into each other on a night mission, killing two people, it was confirmed yesterday.

The aircraft came down north of Baghdad, leaving two military personnel dead and wounding five others. The Ministry of Defence said two people were seriously injured and three others escaped with minor cuts and bruises. The MoD said it did not believe the helicopters had been shot down and the most probable cause was that they had collided in the dark.

The accident happened late on Saturday and involved two Puma helicopters ferrying special forces to and from operations assisting US forces. One of the dead was a helicopter crew member, the other was believed to have been from the SAS. Military sources said the wreckage and the bodies would be recovered.

British forces are based in southern Iraq but carry out and assist in missions all over the occupied country. The MoD said the next of kin of those killed and injured in the incident had been informed, but it would not release names or details of the units involved until today.

At first it was reported that the crash involved US forces, but in a statement Des Browne, the defence secretary, said: "Now that next of kin have been informed, I can confirm that the two helicopters reported this morning as having crashed north of Baghdad earlier today were, in fact, both UK helicopters."

"My thoughts and sympathy are with them and their families. Initial reports indicate that the crash was an accident and not as a result of an attack by insurgents."

The crash brought the total number of UK military deaths since the hostilities in Iraq began in 2003 to 142. Of those, 109 have died in action. The rest were accidents or linked to natural causes or illness, remain unexplained, or are still under investigation. A total of 32 British military personnel have died in transportation accidents involving three different types of helicopters and planes since the invasion.

An MoD spokesman said: "The Puma has an excellent safety record and plays an important role in Iraq in the movement of individuals and equipment."

Meanwhile, Tony Blair told the BBC's Politics Show yesterday that despite the pain of the latest loss of UK life in Iraq, British forces needed to stay there to "fight extremism and terrorism".